* todos.el: Use tab instead of spaces to indent.

* todos.el: Use tab instead of spaces to indent.
(todos-indent-to-here): Change default value.
(todos-modes-set-1): Make tab-width a local variable and set it to
todos-indent-to-here.
(todos-insert-item-1, todos-edit-item): Use tab not spaces to indent.
(todos-edit-quit): Use tab not spaces to indent and fix omission of item.